A Comprehensive Guide to Software Testing Life Cycle (STLC)

Relia Software

Relia Software

Ngoc Den

Relia Software

Software Development

The Software Testing Life Cycle (STLC) is a strategic roadmap that guides testers throughout the development process to guarantee high-quality software.

software testing life cycle

Table of Contents

Software testing is always essential and goes along with the software development life cycle (SDLC) to enhance the software product functions and quality. It is assumed as the most important part of developing software products. 

So why is this important? To give you the best answer, this article will delve into the Software Testing Life Cycle (STLC), explaining its importance, different phases, benefits, challenges, and best practices.

What is the Software Testing Life Cycle (STLC)?

The Software Testing Life Cycle (STLC) is a strategic roadmap that guides software testers throughout the development process. It ensures a systematic approach to identifying and fixing bugs, ultimately guaranteeing the release of high-quality software. 

STLC interacts seamlessly with each phase of the Software Development Life Cycle (SDLC), from concept to launch. It focuses on testing components and modules in software development to ensure the quality before reaching end users. The STLC is frequently divided into six distinct phases, each with well-defined objectives and deliverables. 

STLC model phases
6 Software Testing Life Cycle Phases (Source: Internet)

6 Software Testing Life Cycle Phases

Phase 1: Requirement Analysis  

This initial phase establishes the groundwork for successful testing. Testers will analyze the requirements to comprehend the software's functionalities, features, and intended behavior. Requirements can be broadly categorized into:

  • Functional Requirements: Specify what the software should be able to accomplish (e.g., login capabilities, data processing).
  • Non-functional Requirements: Address performance expectations (speed, scalability), usability, compatibility, etc.

>> Read more: Differences Between Functional and Non-Functional Testing

By thoroughly understanding these requirements, testers may create effective test cases that guarantee the product's function. This phase might also involve techniques like black-box testing (focusing on external behavior) or white-box testing (focusing on internal code structure)  to identify potential risks and places where problems may occur.

Phase 2: Test Planning

With a clear grasp of requirements, the next step is to develop a strategic test plan. This roadmap describes the full testing process, including:

  • Testing Scope: Specifying which functionalities will be tested and which may be excluded.

  • Testing Levels: Choosing the levels of testing to undertake (unit test, integration test, system test, and acceptance test).

  • Testing Resource: Estimating testing resources such as manpower, tools, and hardware.

  • Risk Management:  Identifying potential risks and developing mitigation solutions.

  • Defect Reporting and Tracking: Setting up a system for reporting and tracking defects during the testing process.

Creating a well-defined test strategy promotes a focused and efficient testing process, reducing the possibility of missing important details.

Phase 3: Test Case Development

Testers methodically design test cases based on the test plan and requirements. These precise instructions specify the specific steps, expected results, and successful or unsuccessful criteria for each test. They can be classified as:

The quality of test cases has a substantial impact on the overall success of the testing process. Well-designed test cases ensure that all software capabilities and potential vulnerabilities are covered.

Phase 4: Test Environment Setup

Before executing the test cases, a testing environment is carefully built up. This environment simulates the real-world situations in which the software will be utilized. It includes:

  • Hardware and Software Setup: Involves setting up the required hardware and software platforms for testing.

  • Data Preparation: Requires generating sample data sets that reflect real-world scenarios.

A well-configured testing environment guarantees that tests are run in a realistic setting, reducing the likelihood of meeting production-specific difficulties later. Configuration management tools can be crucial for maintaining a stable and consistent testing environment.

Phase 5: Test Execution

This phase is critical for discovering defects and verifying that the product works as planned. Testers carefully execute the created test cases by strictly adhering to the instructions. Generally, this step involves comparing the software’s actual behavior to the expected outcome, and any differences are classified as bugs.

The Test Execution Phase includes:

  • Unit testing: Testing individual software units (such as functions and modules).

  • Integration testing: Determining how distinct components interact with one another.

  • System testing: Testing the overall software system.

  • Acceptance testing: Testing the user experience when end-users interact with the software.

Phase 6: Test Cycle Closure

This final phase guarantees that the testing effort is well documented and facilitates informed decisions to produce a high-quality software product. This step involves:

  • Defect Analysis and Reporting: Identifying faults, prioritizing them depending on severity (critical, major, minor), and reporting them to developers for resolution.

  • Test Result Reporting: Creating a detailed report that summarises the testing process, findings, and overall program quality.

  • Test Closure Meeting: Discussing testing results with stakeholders and determining the next actions based on the findings. This might involve regression testing to ensure fixed bugs don't reappear in subsequent releases.

Benefits of Software Testing Life Cycle

Enhanced Software Quality

STLC prioritizes identifying and correcting flaws early to prevent them from becoming serious difficulties. This also helps to reduce end-user faults, making software more stable and reliable.

Reduced Development Costs

Catching issues early in development is far cheaper than repairing them later. STLC reduces post-deployment rework and speeds up time-to-market by preventing major issues from delaying releases.

Improved User Satisfaction

STLC ensures user satisfaction by delivering high-quality software with fewer problems, and a stable, user-friendly experience. This can lead to increased user happiness and loyalty, which is likely to promote your program and boost your brand reputation.

Early Risk Mitigation

STLC finds flaws and dangers early in development by proactively analyzing requirements and arranging testing. These early risk mitigation measures reduce development delays.

Increased Efficiency Development

A clear STLC guides testing through specific objectives, test cases, and procedures. This simplifies development by reducing confusion and rework.

Improved Communication and Collaboration

STLC fosters better communication and collaboration between testers, developers, and other stakeholders. Regular testing feedback loops keep everyone informed about identified issues and their resolutions. This collaborative environment promotes a shared understanding of the project goals and ensures everyone works towards delivering a high-quality software product.

benefits of software testing lifecycle
Software Testing Lifecycle Benefits (Source: Internet)

STLC Challenges and Solutions

Resource Constraints

Testing needs skilled developers, specialized equipment, and time set. When these resources are limited, it can be hard to carry out a full STLC.


  • Prioritize testing essential features and user journeys.

  • Use automation techniques to streamline repetitive testing processes and free up resources for complicated testing.

  • Outsource specific testing activities to supplement internal resources.

Defect Management Challenge

Efficiently identifying, managing, and tracking bugs are crucial for a successful remediation.


  • Track, prioritize, and assign defects to developers for resolution by using defect tracking systems.

  • Create a clear, consistent bug-reporting format.

  • Keep testers and developers informed about defect reports, remedies, and any follow-up actions required.

Testing Complex Systems

Modern software systems can be intricate with interconnected components. Testing the functionality and compatibility of these complex systems can be a daunting task.


  • Break down the system into smaller, more manageable modules. Test each module of the system separately.

  • Use well-defined integration testing methodologies to verify module compatibility.

  • Use complicated system testing tools that can handle the complexities of modern software architectures.

Keeping Up with Technology Advancements

The software development landscape is constantly evolving. Testers need to stay updated with emerging technologies and testing methodologies.


  • Encourage testers to attend workshops and training programs to keep current.

  • Keep up with industry best practices and new testing tools by ongoing research.

Best Practices for Software Testing Life Cycle

  • Test Early and Often: Include testing throughout the development process, not just at the end.

  • Automate the Ordinary: Use automation tools to streamline repetitive testing tasks and free up your testing resources to focus on complex scenarios 

  • Document Everything: Keep clear records of requirements, test plans, cases, and defect reports for better communication, knowledge transfer, and repeatability.

  • Continuous Improvement: Monitor the effectiveness of STLC regularly and adjust your approach based on results.

  • Invest in Testers: Equip your team with the latest testing knowledge and skills by providing opportunities for training and professional development.

  • Prioritize Risks: Focus your testing efforts on the areas with the highest potential impact.

  • Collaborate and Engage: Encourage open communication among testers, developers, and stakeholders to make the working process smooth during testing.

  • Effective Change Management: Adapt testing to accommodate evolving features and functionalities.

  • Track and Analyse: Gather and analyze test metrics to pinpoint areas for improvement.

software testing life cycle best practice
Best Practices of Software Testing Lifecycle (Source: Internet)

>> Read more:


Software Testing Life Cycle (STLC) has to be linked with the software development life cycle (SDLC) to spot errors early on, optimize resources, increase communication, ensure a smooth workflow, and improve software quality. This alignment ensures thorough testing at each development phase, resulting in high-quality software that fulfills user expectations.

>>> Follow and Contact Relia Software for more information!

  • testing